Did you brush it or spray it?Steve;
I used this on my aluminum panels.
View attachment 94779View attachment 94780You have a choice of yellow (actually greenish-yellow) or green zinc chromate.
First, scuff the surface with Scotchbrite and then treat the surface with a phosphoric acid solution, then rinse thoroughly and let dry. Apply the primer per instructions and you have a nice hard surface that is ready to top coat. I used an aerospace grade isocyanate polyurethane yellow over this primer on my steel tube chassis but I left the aluminum in primer because I liked the "aircraft" look.
Great advice, thanks NeilSteve;
My choice was the yellow zinc chromate in a quart size. I sprayed it on with a $9.99 on-sale spray gun from Harbor Freight. At that price you can throw it away instead of cleaning it. Buy the quart or gallon-size containers and spray it yourself. The small spray cans are OK for small jobs or touch-ups but not for larger panels. I'd suggest spraying all your panels at the same time.